40018561 has 8 divisors (see below), whose sum is σ = 46224864. Its totient is φ = 34240320.

The previous prime is 40018543. The next prime is 40018567. The reversal of 40018561 is 16581004.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 40018561 - 2¹⁷ = 39887489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40018567) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 106815 + ... + 107188.

It is an arithmetic number, because the mean of its divisors is an integer number (5778108).

Almost surely, 2^40018561 is an apocalyptic number.

It is an amenable number.

40018561 is a deficient number, since it is larger than the sum of its proper divisors (6206303).

40018561 is a wasteful number, since it uses less digits than its factorization.

40018561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214031.

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 40018561 is about 6326.0225260427. The cubic root of 40018561 is about 342.0480792613.

Adding to 40018561 its reverse (16581004), we get a palindrome (56599565).

The spelling of 40018561 in words is "forty million, eighteen thousand, five hundred sixty-one".